If “Nick Harkaway” sounds like the made-up name of a superhero, you’re half right. He is a super writer, and that comic-book-inspired name is the pseudonym of Nicholas Cornwell, who’s the son of John le Carré, which is the pseudonym of David John Moore Cornwell, who once worked for MI5 and MI6 — so who knows if any of this is actually true.

Trust me, though, when I say that Harkaway’s new novel, “Tigerman,” is an irresistible delight, something like “Major Pettigrew’s Last Stand” as played by James Bond. The plot whizzes past inventive toward ridiculously improbable, but what really makes “Tigerman” roar is its captivating blend of tones — from the light hues of domestic comedy to the bold colors of Spider-Man. And Harkaway doesn’t stop there: Like some Marvel mad scientist, he has crossed strains of a modern-day environmental crisis with the sweet story of a veteran of the Afghan war trying to adopt a little boy.

Our hero — so dutiful, so modest, so lonely — is 39-year-old Sgt. Lester Ferris. Scarred from battle, he’s enjoying a quiet assignment as the British consul on the island of Mancreu in the Arabian Sea. Since Britain handed this remote, mountainous paradise over to NATO, the sergeant’s primary duty is to offer cheery hellos to the remaining residents.

And there are fewer residents every month. “No one was Staying,” Harkaway writes. “Staying meant dying when the island died, and then there’d be nothing left to die for.” Decades of chemical manufacturing and careless disposal have poisoned the island. In 2004, seismic movement released the first of several Discharge Clouds — eruptions of caustic gas and newly formed microbes that cause frightening illnesses and birth defects. Before the “symbiotic bugs” can spread, the world’s governments decide, the island must be evacuated and sterilized by fire. “Mancreu became a kind of Casablanca,” Harkaway writes, “possessed of an uncertain legal status by virtue of the sentence of death, expropriated from its notional sovereignty by the international will, gladly yielded up to its doom, yet still there and officially claimed by no one.”

This is the apocalypse writ small: the end of the world in pressed khakis with regular tea time. Or at least that’s the official plan. Harkaway uses this remote Superfund site to sketch the hideous underbelly of modern civilization. Floating out in Mancreu’s bay is the Black Fleet, unaligned ships drawn from various nations and corporations. Suspended in legal limbo and about to be incinerated, the island offers a convenient spot for “prisons for deniable detainees and hospitals for unethical procedures; data havens, grey banks, untaxed subsidiaries; floating harems and forced-labour factories, auction houses for contraband goods; torture facilities for hire.”

"Tigerman" by Nick Harkaway. (Knopf)

All of that officially nonexistent horror is supposed to stay out in the bay — and out of the news — but early in “Tigerman,” while Ferris is enjoying his tea, armed bandits burst into a cafe and murder its owner. Only Ferris’s heroics with a biscuit tin keep the carnage from being worse. In that moment, he wins the admiration of a 10-year-old island native who calls himself Robin (as in Batman &) and speaks in a curious patois of pop culture and gamer slang. “We are made from awesome!” the boy shouts while looking over the bandits’ bodies in the cafe. “Emote later. Right now: Voight-Kampff FTW.”

DC Comics never launched a crime-fighting duo quite this touching. Ferris, haunted by “a ghastly aloneness which made the world black around him,” is determined to show Robin that goodness prevails — and to prove that he’s worthy of the boy’s devotion. Robin, meanwhile, is a slippery orphan, desperately poor but as adept with technology as any tween in the West. Determined not to look like “an old fart,” Ferris sits down with the boy, and together they page through his comics collection, designing their own superhero. The resulting figure — Tigerman — is an absurd amalgamation of metal shields, a gas mask and bits of fur and bone — but no gun. When he tries to talk, Ferris sounds like a kazoo, but that’s not what Robin hears. “It was made and designed by the House of Awesome,” the boy declares, “from materials found in the deep awesome mines of Awesometania, and it would be recorded in the Annals of Awesome.”

In the novel’s most touching parts, Harkaway captures the wonder of youthful enthusiasm, what we used to feel when making a fort from a refrigerator box or launching water balloons with giant rubber bands. But he sets all that childhood frivolity in the context of a rapidly collapsing society. The sergeant’s great challenge — and the novel’s — is somehow to satisfy the boy’s thirst for justice while combating an increasingly violent series of crimes — “to show what one man — one hero — could do on a dark night in a town on the edge.”

Since the British government insists that Ferris remain uninvolved in this mess, the bizarre costume comes in handy for disguising his mild-mannered identity, confusing his superstitious combatants and infusing himself with otherworldly energy. Indeed, in several spectacular scenes spiked with explosives and wit, Tigerman performs crazy feats of derring-do that Jack Reacher and Jason Bourne could only dream of. (Are you paying attention, Hollywood?)

But even with bullets ricocheting and rockets flying, what really terrifies the man inside the Tigerman costume is the thought of losing Robin. Ferris has “no direct experience with the violent woes and self-reproaches of children,” and he has no language with which to express his affection. Harkaway, though, finds the words to make those feelings clear.

Just as it’s easy for the residents of Mancreu to forget the Black Fleet in the bay, it’s easy for us to ignore the darker currents of this novel. The touches of sentimentality, Ferris’s awkward romance with an island scientist, the sweet comedy of an accomplished soldier disarmed by a 10-year-old child — these elements lull us into imagining that “Tigerman” must eventually curl up into some predictably warm embrace.

But Harkaway is a far tougher storyteller than that, and the battle in which Ferris and Robin are engaged is ultimately no comic-book fantasy, just as a poisoned island is no paradise. You won’t see the next punch coming. “A proven track record of insane idealism” can’t help a man leap tall buildings in a single bound or make evil governments behave. But that doesn’t keep this brave sergeant from trying. Sure, any kid would want to be Tigerman. In the end, though, Ferris is the real hero worth emulating.

Charles is the editor of Book World. His reviews appear in Style every Wednesday. You can follow him on Twitter @RonCharles.

TIGERMAN

By Nick Harkaway

Knopf. 337 pp. $26.95

Ron Charles is the editor of The Washington Post's Book World. For a dozen years, he enjoyed teaching American literature and critical theory in the Midwest, but finally switched to journalism when he realized that if he graded one more paper, he'd go crazy.

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